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Fall 2026 Rehearsal — Section I: Multiple Choice

A current-format rehearsal

This is original generated practice for the course effective Fall 2026, whose revised exam begins in May 2027. These are not official College Board questions. The preserved earlier practice test remains available as historical source material; this rehearsal uses the revised format and its own new task identities.

Allow 90 minutes for all 42 questions. Every question has four choices and one defensible answer. A graphing calculator with statistical capabilities is expected. Keep appropriate statistical formulas and tables available. Questions 12–14 share a probability setting, and questions 36–38 share a regression setting. The complete setting is repeated with each question so that a page position or screen reader does not hide needed information.

A deliberate first pass

Before calculating, identify what is being measured and what the question asks you to produce. A count of people with a yes/no response suggests a proportion; a measured time or distance suggests a quantitative mean. A paired design gives one set of within-unit differences, while two separately selected groups give independent samples. The design determines the parameter and procedure before a calculator command does.

Read the subtraction order, conditioning event, and direction of a hypothesis carefully. In a conditional probability, the denominator is the group you are given. For a residual, use observed minus predicted. A difference defined as A minus B has a negative sign when A is lower. These small details can change an otherwise sensible calculation.

For an interval or test, separate the statistic from the parameter. A confidence interval estimates an unknown population value. A p-value describes how unusual the observed result would be under a specified null model. Neither attaches a probability to the hypothesis being true, and neither automatically supports a cause-and-effect conclusion. For a mean with unknown population standard deviation, the estimated standard error contains s/ns/\sqrt n rather than s/ns/n.

When a graph or table is supplied, use its labels and units. Relative frequencies allow fair comparisons between differently sized groups. A residual pattern can reveal curvature even when the residuals average to zero. If a question asks about a simulated probability, count the qualifying simulation trials and divide by the total number of trials; do not silently replace the requested empirical estimate with a theoretical probability.

Using the 90 minutes

Forty-two questions in 90 minutes allow a little over two minutes per question on average. Make a first pass through questions you can resolve, record a choice, and revisit any that need a longer calculation. Check that a calculator output corresponds to the right model, parameter, degrees of freedom, and tail. Keep a few intermediate digits, then round to the precision of the choices. No rehearsal timer is enforced here, so set your own timer for a timed attempt.

Attempt the section before opening its separate worked answers. Afterward, use the explanations to identify whether a missed item came from model choice, a numerical step, a sign or unit, or the meaning of the result. Correct a reasoning error in words as well as changing a choice. The explanations are reviewed separately from the prompts; the answer page does not establish that a learning objective is mastered.

Original generated practice for the Fall 2026 course.

1. Cycling commute distance

A town has 12,000 registered cyclists. A transportation planner will randomly select 200 of them and record each cyclist’s total cycling commute distance, in miles, during a specified week. The planner wants to estimate a population mean.

Part a

Which is a valid investigative question that matches this purpose and the data to be collected?

Worked answer and rubric

2. Support for a proposed walkway

A city planner will independently select random samples of registered voters from the east and west districts. Each voter will answer the same yes/no question about support for a proposed public walkway. The planner wants to investigate whether population support differs between the districts.

Part a

Which investigative question fits the study?

Worked answer and rubric

3. Sampling apartment buildings

A housing agency divides its service area into 80 apartment buildings. It randomly selects 8 buildings and surveys every household in each selected building. The buildings have broadly similar mixes of household sizes.

Part a

Which sampling method is described?

Worked answer and rubric

4. A bus-service feedback poll

A transit agency places an optional online poll on its website asking riders to rate the bus service. Only riders who choose to visit the website and submit a response are included. The agency uses the results to estimate the proportion of all riders who are dissatisfied.

Part a

Which is the clearest potential source of bias?

Worked answer and rubric

5. Diet and starting age

A researcher will compare two diets for 80 kittens. Forty kittens are 8 weeks old and forty are 16 weeks old. Starting age is expected to affect weight gain. Each kitten will receive one diet for the same period.

Part a

Which allocation best addresses the known age effect while allowing a comparison of the diets?

Worked answer and rubric

6. Volunteers and a sleep program

Sixty adults volunteer for a study. They are randomly assigned to a new sleep program or a control program. Procedures other than the assigned program are the same, and the new-program group has a convincingly greater average improvement in nightly sleep duration.

Part a

Which conclusion is best supported by the design?

Worked answer and rubric

7. Sample standard deviation

A student records the checkout times, in minutes, for four randomly selected library visits: 2, 4, 4, and 6.

Part a

What is the sample standard deviation of these four times, in minutes?

Worked answer and rubric

8. Representing two commute modes

A university wants to estimate mean commute time for its students. Bus commuters and rail commuters may have different travel-time distributions. A complete student list identifies each commuter’s mode. The university can contact a randomly chosen student in either group at the same cost.

Part a

Which plan is most appropriate if the university wants both commute modes represented through random selection?

Worked answer and rubric

9. Checkout-time shape

The dotplot shows checkout times, in minutes, for 12 visits. Each dot represents one visit.

Dotplot: one visit at 0 minutes, six at 1, three at 2, one at 3, and one at 9; no visits from 4 through 8.
Checkout time for 12 visits, in minutes.

Part a

Which description best fits the distribution?

Worked answer and rubric

10. Comparing delivery routes
Delivery-time summaries, in minutes
RouteMinimumQ1MedianQ3Maximum
A810121432
B1012141620

The summaries describe two separate samples of deliveries.

Part a

Which comparison is supported by the summaries?

Worked answer and rubric

11. A new invitation

Two hundred employees volunteer for a training study. They are randomly assigned, 100 per group, to receive either the standard invitation or a new invitation. Enrollment within one week is recorded as yes or no. The researcher’s goal is to determine whether the new invitation increases enrollment.

Part a

Which investigative question best includes the study’s response, direction, and defensible causal scope?

Worked answer and rubric

12. A conditional refund probability

Probability set: questions 12–14. An airline has complete records for 200 passengers on one flight. A passenger will be selected uniformly at random from these 200. Let A mean that the passenger used the airline app, and let R mean that the passenger claimed a refund. The table classifies every passenger once.

App use and refund claims
Refund RNo refundTotal
Used app A7248120
Did not use app206080
Total92108200

Part a

What is P(R∣A)P(R\mid A)?

Worked answer and rubric

13. App use or a refund

Probability set: questions 12–14. An airline has complete records for 200 passengers on one flight. A passenger will be selected uniformly at random from these 200. Let A mean that the passenger used the airline app, and let R mean that the passenger claimed a refund. The table classifies every passenger once.

App use and refund claims
Refund RNo refundTotal
Used app A7248120
Did not use app206080
Total92108200

Part a

What is P(A∪R)P(A\cup R), the probability that the selected passenger used the app or claimed a refund, or both?

Worked answer and rubric

14. An independence benchmark

Probability set: questions 12–14. An airline has complete records for 200 passengers on one flight. A passenger will be selected uniformly at random from these 200. Let A mean that the passenger used the airline app, and let R mean that the passenger claimed a refund. The table classifies every passenger once.

App use and refund claims
Refund RNo refundTotal
Used app A7248120
Did not use app206080
Total92108200

Part a

If A and R were independent while keeping their observed marginal probabilities, what would P(A∩R)P(A\cap R) equal? Compare this benchmark with the actual table.

Worked answer and rubric

15. Inspecting a small battery batch

A batch contains 12 batteries, exactly 4 of which are defective. An inspector randomly selects 10 batteries without replacement. Let X be the number of defective batteries selected.

Part a

Why is X not a binomial random variable?

Worked answer and rubric

16. Daily loan requests

For a small equipment desk, X is the number of loan requests during a particular hour. The probability model below gives all possible values.

Probability distribution for X
x (requests)0123
P(X=x)0.100.300.400.20

Part a

What is the standard deviation of X, in requests?

Worked answer and rubric

17. The heaviest packages

Package masses follow a normal distribution with mean 500 grams and standard deviation 8 grams. Packages in the heaviest 10% receive an extra handling label.

Part a

Approximately what mass is the lower cutoff for an extra handling label?

Worked answer and rubric

18. A simulated success count

A student simulates 1,000 trials. In each trial, 10 independent spins are made on a spinner with probability 0.20 of landing red, and X is the number of red results. The recorded frequencies are below.

Simulated values of X
X012345678–10
Frequency1052683022048727610

Part a

Using the simulation, estimate P(X≥4)P(X\ge4).

Worked answer and rubric

19. Walking to work

All responses in two separate commuter samples are shown. Each commuter has one primary mode.

Commute modes by district
DistrictWalkTrainDriveTotal
North305020100
South308090200

Part a

Which claim about these samples is supported by conditional relative frequencies?

Worked answer and rubric

20. Repeated sample means

A population of checkout times is moderately right-skewed, with mean 8 minutes and standard deviation 6 minutes. A computer repeatedly draws independent random samples of 36 visits, calculates the mean for each sample, and plots 1,000 such means. The plot is roughly bell-shaped, centered near 8 minutes, with spread near 1 minute.

Part a

What does the plotted distribution represent?

Worked answer and rubric

21. A rare observed response

A simple random sample of 150 adults is selected without replacement from a population of 5,000 adults. Nine sampled adults report using a particular bicycle-sharing service. A researcher proposes a one-sample z-interval for the population proportion using the service.

Part a

Which condition is not satisfied for this interval?

Worked answer and rubric

22. Estimating a difference in proportions

A researcher independently selects random samples of businesses from two districts. In each sample, the response is whether the business has rooftop solar panels. The researcher wants an interval estimate for the proportion with panels in district A minus the proportion with panels in district B. Assume the needed conditions are satisfied.

Part a

Which procedure matches the parameter and goal?

Worked answer and rubric

23. Interpreting a p-value

A researcher tests H0:p=0.40H_0:p=0.40 against Ha:p>0.40H_a:p>0.40, where p is the proportion of all households in a county that compost. The sample is random, all conditions are met, and the observed sample proportion is above 0.40. The p-value is 0.027.

Part a

Which interpretation of the p-value is correct?

Worked answer and rubric

24. A one-proportion test calculation

In a simple random sample of 200 residents from a very large population, 118 support a recycling proposal. A researcher tests H0:p=0.50H_0:p=0.50 against Ha:p>0.50H_a:p>0.50. All conditions for the one-sample z-test are satisfied.

Part a

Which pair is the appropriate test statistic and p-value, approximately?

Worked answer and rubric

25. A missed production problem

A factory tests H0:p=0.02H_0:p=0.02 against Ha:p>0.02H_a:p>0.02, where p is the proportion of defective items from a production line. Rejecting the null stops the line for inspection; failing to reject it leaves the line running.

Part a

Which event is a Type II error?

Worked answer and rubric

26. An interval for two proportions

Independent random samples of households from towns A and B are used to estimate pA−pB, where pA and pB are the proportions of all households with home insulation in the respective towns. A valid 95% confidence interval is (0.04, 0.18).

Part a

Which claim is supported by the interval?

Worked answer and rubric

27. Commute mode and age group

A city selects one simple random sample of 300 adult residents. Each sampled resident is classified by age group (18–39, 40–59, or 60+) and primary commute mode (walk, public transit, or drive). The city wants to test whether the two variables are associated in its adult population. All test conditions are satisfied.

Part a

Which test is appropriate?

Worked answer and rubric

28. An expected count

Independent random samples of people from three training programs give the outcomes below. A chi-square test for homogeneity is planned.

Training outcome counts
ProgramPassedDid not passTotal
A362460
B443680
C402060
Total12080200

Part a

Under the null hypothesis of the same outcome distribution in the three populations, what is the expected count for program B participants who did not pass?

Worked answer and rubric

29. The same machines twice

An engineer measures operating noise, in decibels, for each of 12 machines before and after a modification. The analysis will use each machine’s before-minus-after noise difference. The population standard deviation of these differences is unknown. Assume inference conditions are met.

Part a

Which test is appropriate for whether the modification changes mean noise?

Worked answer and rubric

30. Comparing t-distributions

Consider a t-distribution with 9 degrees of freedom and a t-distribution with 40 degrees of freedom.

Part a

Which comparison is correct?

Worked answer and rubric

31. A mean waiting-time interval

A simple random sample of 16 visits from a population of 5,000 clinic visits has mean waiting time 23 minutes and sample standard deviation 4 minutes. The population waiting-time distribution is approximately normal. For a 95% t-interval with 15 degrees of freedom, use t* = 2.131.

Part a

What is the 95% confidence interval for the population mean waiting time, approximately?

Worked answer and rubric

32. Extreme skewness and n = 30

A population of insurance claims is extremely right-skewed, with a few extraordinarily large claims. A researcher randomly selects 30 claims from a very large population and wants to use a normal model for the sampling distribution of the sample mean.

Part a

Which assessment is most appropriate?

Worked answer and rubric

33. A directional mean comparison

An engineer obtains independent random samples from two processes, A and B. The quantitative response is completion time, in minutes. Let μA and μB be the respective population mean completion times. The engineer wants to know whether process A has a lower mean time.

Part a

Which hypotheses match this question?

Worked answer and rubric

34. A two-mean test statistic

Independent random samples give nA = 40, meanA = 14 minutes, sA = 4 minutes; and nB = 50, meanB = 12 minutes, sB = 5 minutes. All two-sample t-test conditions are satisfied. The null hypothesis is μA−μB = 0.

Part a

What is the two-sample t statistic for A minus B?

Worked answer and rubric

35. Estimating a mean repair-time difference

Independent random samples of 35 repair jobs from city A and 40 repair jobs from city B are obtained. The response is repair time in minutes. The population standard deviations are unknown, and all inference conditions are satisfied. The goal is to estimate an interval for μA−μB, the difference in population mean repair time.

Part a

Which procedure matches this design and estimation goal?

Worked answer and rubric

36. Interpreting correlation

Regression set: questions 36–38. For 18 dairy shops, x is daily cooling time in hours and y is the percentage of products spoiled. The observed x values range from 2 through 8 hours. The scatterplot is approximately linear with no influential outliers. A least-squares model is y^=40−3x\hat y=40-3x, with correlation r=−0.80r=-0.80. These are observational data.

Part a

Which interpretation of r is appropriate?

Worked answer and rubric

37. A predicted spoilage percentage

Regression set: questions 36–38. For 18 dairy shops, x is daily cooling time in hours and y is the percentage of products spoiled. The observed x values range from 2 through 8 hours. The scatterplot is approximately linear with no influential outliers. A least-squares model is y^=40−3x\hat y=40-3x, with correlation r=−0.80r=-0.80. These are observational data.

Part a

What spoilage percentage does the model predict for a shop with 6 hours of daily cooling?

Worked answer and rubric

38. A spoilage residual

Regression set: questions 36–38. For 18 dairy shops, x is daily cooling time in hours and y is the percentage of products spoiled. The observed x values range from 2 through 8 hours. The scatterplot is approximately linear with no influential outliers. A least-squares model is y^=40−3x\hat y=40-3x, with correlation r=−0.80r=-0.80. These are observational data.

A shop with 6 hours of cooling has an observed spoilage percentage of 19%.

Part a

What is this shop’s residual, in percentage points?

Worked answer and rubric

39. Curvature in residuals

The residual plot below comes from fitting a least-squares line to five paired quantitative observations. The explanatory variable x is measured in hours and the residual is in output units. Each point is one observation.

Residual plot with points (1,2), (2,−1), (3,−2), (4,−1), and (5,2), forming a U-shaped pattern.
Residuals versus x, with the zero-residual line shown.

Part a

What does the visible pattern suggest?

Worked answer and rubric

40. An intercept beyond the data

A least-squares line predicts bus travel time y, in minutes, from route distance x, in kilometers: y^=8+2.5x\hat y=8+2.5x. The observed distances range from 3 to 15 kilometers.

Part a

Which interpretation of the intercept is most appropriate?

Worked answer and rubric

41. Explained price variation

For a sample of fruit boxes, a least-squares line predicts sale price y from box mass x. The correlation is r = 0.90, and a straight-line model is appropriate for the observed range.

Part a

Which calculation and interpretation of the coefficient of determination are correct?

Worked answer and rubric

42. Fitting a least-squares line

For five comparable shifts, x is the number of employees at a service counter and y is completed orders per minute. The paired observations are below. Use technology or a least-squares calculation to fit y on x.

Employees and completed orders
x (employees)12345
y (orders/minute)24546

Part a

Which is the least-squares regression line?

Worked answer and rubric

Glossary and deeper reading · 10 refreshers

These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.

  • Probability

    Probability quantifies how likely an event is under a specified chance model. It lies between 0 and 1, with larger values representing greater likelihood. For example, drawing a red card from a well-shuffled standard deck has probability one half.

    Read more: Probability in the captured Statistics reading →

  • Statistical independence

    Statistical independence means that learning one outcome does not change the probability distribution of another. For two events, it implies that the probability of both occurring equals the product of their probabilities. For example, independent draws with replacement keep the second draw’s color probabilities unchanged by the first.

    Read more: Statistical independence in the captured Statistics reading →

  • Sample

    A sample is the subset of a population actually studied. How it is selected matters for the conclusions that can be drawn about the population. For example, 60 selected students may be a sample from a school’s full enrollment.

    Read more: Sample in the captured Statistics reading →

  • Event in probability

    An event is a set of outcomes from a chance process’s sample space. The event occurs when the observed outcome belongs to that set. For example, rolling an even result is the event containing 2, 4, and 6 for a six-sided die.

    Read more: Event in probability in the captured Statistics reading →

  • Conditional probability

    Conditional probability measures the likelihood of one event when another event is known to have occurred. It restricts attention to the conditioning event, which must have positive probability. For example, knowing a drawn card is a face card changes the denominator when finding the probability it is a queen.

    Read more: Conditional probability in the captured Statistics reading →

  • Sample statistic

    A statistic is a numerical summary calculated from sample data. Its value can change when a different sample is selected from the same population. For example, the proportion of walkers among 60 sampled students is a statistic.

    Read more: Sample statistic in the captured Statistics reading →

  • Population parameter

    A population parameter is a numerical feature of the population or probability model being studied. It is fixed for that defined population, although its value may be unknown. For example, the true proportion of all enrolled students who walk to school is a parameter.

    Read more: Population parameter in the captured Statistics reading →

  • Relative frequency

    Relative frequency is a group’s count divided by the total count. It can be written as a proportion or multiplied by 100 to give a percentage. For example, 8 choices out of 20 have relative frequency 0.4, or 40%.

    Read more: Relative frequency in the captured Statistics reading →

  • Residual

    A residual is an observed response minus its predicted response. A positive residual places the observed point above the fitted line, while a negative residual places it below. For example, an observed height of 18 centimeters and a predicted height of 16 centimeters give a residual of 2 centimeters.

    Read more: Residual in the captured Statistics reading →

  • Degrees of freedom

    Degrees of freedom describe the independent information remaining after constraints or estimated quantities are accounted for. The value depends on the procedure, rather than always being the sample size minus 1. For example, a one-sample t procedure uses n − 1 degrees of freedom, while simple regression inference uses n − 2.

    Read more: Degrees of freedom in the captured Statistics reading →

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